In the fields of home and building automation, there has been an increasing interest in controllable lighting systems. In such systems, there is a growing trend in the application of connectable modules for luminaires and adjacent applications. By way of example, some connectable modules may be used to allow a luminaire to communicate with a central controller or hub, or allow a sensor to connect to a luminaire in order to pass information about the environment.
It has been recognised that one of the challenges in realizing such systems is in ensuring effective power delivery and communication capabilities between a luminaire and the connectable modules. This issue is especially prevalent in areas of high humidity or dust, such as outdoor environments or even bathrooms and wet rooms, which require devices with sufficient ingression protection (IP) isolation.
It is known that power isolation between a luminaire and a connectable module may be provided through use of a wireless power transfer system. In order to ensure isolated communication between a luminaire and a connectable module, it is known to use an isolated communication interface, which typically incorporates opto-couplers and the like.
WO2011/041816 shows an DALI interface according prior art. WO2016/032928 shows different possibilities to implement DALI in an insulated manner without indicating how it can be implemented using the transformer only, in particular how to implement a return path without complexifying the circuit.